U.S. patent application number 10/302328 was filed with the patent office on 2004-05-27 for methods of fabricating integrated circuitry.
Invention is credited to Connell, Mike, Jiang, Tongbi.
Application Number | 20040102022 10/302328 |
Document ID | / |
Family ID | 32324742 |
Filed Date | 2004-05-27 |
United States Patent
Application |
20040102022 |
Kind Code |
A1 |
Jiang, Tongbi ; et
al. |
May 27, 2004 |
Methods of fabricating integrated circuitry
Abstract
A substrate including a plurality of integrated circuitry die is
fabricated or otherwise provided. The individual die have bond
pads. A passivation layer comprising a silicone material is formed
over the bond pads. Openings are formed through the silicone
material to the bond pads. After the openings are formed, the die
are singulated from the substrate. In one implementation, a method
of fabricating integrated circuitry includes providing a substrate
comprising a plurality of integrated circuitry die. Individual of
the die have bond pads. A first blanket passivation layer is formed
over the substrate in contact with the bond pads. A different
second blanket passivation layer comprising silicone material is
formed over the first passivation layer. Openings are formed
through the first and second passivation layers to the bond pads.
After the openings are formed, the die are singulated from the
substrate. Other aspects and implementations are contemplated.
Inventors: |
Jiang, Tongbi; (Boise,
ID) ; Connell, Mike; (Boise, ID) |
Correspondence
Address: |
WELLS ST. JOHN P.S.
601 W. FIRST AVENUE, SUITE 1300
SPOKANE
WA
99201
US
|
Family ID: |
32324742 |
Appl. No.: |
10/302328 |
Filed: |
November 22, 2002 |
Current U.S.
Class: |
438/458 ;
257/E21.279; 257/E21.293; 257/E21.577; 257/E23.134 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 21/3185 20130101; H01L 21/31612 20130101; H01L 21/76802
20130101; H01L 21/561 20130101; H01L 2924/0002 20130101; H01L
23/3192 20130101; H01L 21/78 20130101; H01L 2924/00 20130101 |
Class at
Publication: |
438/458 |
International
Class: |
H01L 021/30 |
Claims
1. A method of fabricating integrated circuitry comprising:
providing a substrate comprising a plurality of integrated
circuitry die, individual of the die having bond pads; forming a
passivation layer comprising a silicone material over the bond
pads; forming openings through the silicone material to the bond
pads; and after forming the openings, singulating the die from the
substrate.
2. The method of claim 1 comprising forming the passivation layer
comprising silicone material to have a Young's modulus of no
greater than 9.0 GPa.
3. The method of claim 1 wherein the forming of openings comprises
photolithography and etch utilizing photoresist that is completely
removed from the substrate prior to the singulating.
4. The method of claim 1 wherein the forming of openings comprises
photolithography and etch utilizing a photosensitive substance that
comprises a part of the singulated die.
5. The method of claim 1 wherein the passivation layer comprising
silicone material is not formed in contact with the bond pads.
6. The method of claim 1 comprising after the singulating,
contacting the passivation layer comprising silicone material with
a solid particle containing resin.
7. The method of claim 1 comprising forming the passivation layer
comprising silicone material over a passivation layer comprising
polyimide.
8. The method of claim 1 comprising forming the passivation layer
comprising silicone material on a passivation layer consisting
essentially of polyimide.
9. The method of claim 1 comprising forming the passivation layer
comprising silicone material over a passivation layer comprising
silicon nitride.
10. The method of claim 1 comprising forming the passivation layer
comprising silicone material on a passivation layer consisting
essentially of silicon nitride.
11. The method of claim 1 wherein the die as singulated from the
substrate comprise an outermost layer predominately comprising the
passivation layer comprising silicone material.
12. The method of claim 1 comprising forming the passivation layer
comprising silicone material over another passivation layer, and
forming openings to the bond pads through the another passivation
layer prior to forming the passivation layer comprising silicone
material.
13. The method of claim 1 comprising forming a silicon dioxide
comprising passivation layer over the bond pads; forming a silicon
nitride comprising passivation layer over the silicon dioxide
comprising passivation layer; forming openings through the
passivation layer comprising silicon nitride and through the
passivation layer comprising silicon dioxide to the bond pads;
forming a passivation layer comprising polyimide over the
passivation layer comprising silicon nitride and to within the
openings formed through the passivation layer comprising silicon
nitride and the passivation layer comprising silicon dioxide; the
passivation layer comprising silicone material being formed over
the passivation layer comprising polyimide; and the openings
through the silicone material to the bond pads also being formed
through the passivation layer comprising polyimide.
14. A method of fabricating integrated circuitry comprising:
providing a substrate comprising a plurality of integrated
circuitry die, individual of the die having bond pads; forming a
passivation layer comprising a photoimageable silicone material
over the plurality of die; photopatterning the passivation layer
comprising a photoimageable silicone material with actinic energy
effective to change solubility in a solvent of selected regions of
the passivation layer which are received over the bond pads;
exposing the photopatterned passivation layer to the solvent
effective to remove the selected regions from over the bond pads;
and after the exposing, singulating the die from the substrate.
15. The method of claim 14 wherein the photopatterning is void of
any photoresist layer received over the passivation layer
comprising photoimageable silicone material.
16. The method of claim 14 comprising: providing at least one
additional passivation layer intermediate the passivation layer
comprising photoimageable silicone; and after the exposing and
before the singulating, etching the at least one additional
passivation layer through the removed selected regions using the
passivation layer comprising photoimageable silicone material as a
mask and effective to expose the bond pads.
17. The method of claim 16 wherein the photopatterning is void of
any photoresist layer received over the passivation layer
comprising photoimageable silicone material, and the etching is
void of any photoresist layer received over the passivation layer
comprising photoimageable silicone material.
18. The method of claim 14 comprising after the singulating,
contacting the passivation layer comprising silicone material with
a solid particle containing resin.
19. The method of claim 14 comprising forming the passivation layer
comprising silicone material to have a Young's modulus of no
greater than 9.0 GPa.
20. The method of claim 14 wherein the passivation layer comprising
silicone material is not formed in contact with the bond pads.
21. The method of claim 14 comprising forming the passivation layer
comprising silicone material over a passivation layer comprising
polyimide.
22. The method of claim 14 comprising forming the passivation layer
comprising silicone material on a passivation layer consisting
essentially of polyimide.
23. The method of claim 14 comprising forming the passivation layer
comprising silicone material over a passivation layer comprising
silicon nitride.
24. The method of claim 14 comprising forming the passivation layer
comprising silicone material on a passivation layer consisting
essentially of silicon nitride.
25. The method of claim 14 wherein the die as singulated from the
substrate comprise an outermost layer predominately comprising the
passivation layer comprising silicone material.
26. The method of claim 14 comprising forming the passivation layer
comprising silicone material over another passivation layer, and
forming openings to the bond pads through the another passivation
layer prior to forming the passivation layer comprising silicone
material.
27. The method of claim 14 comprising forming a silicon dioxide
comprising passivation layer over the bond pads; forming a silicon
nitride comprising passivation layer over the silicon dioxide
comprising passivation layer; forming openings through the
passivation layer comprising silicon nitride and through the
passivation layer comprising silicon dioxide to the bond pads;
forming a passivation layer comprising polyimide over the
passivation layer comprising silicon nitride and to within the
openings formed through the passivation layer comprising silicon
nitride and the passivation layer comprising silicon dioxide; the
passivation layer comprising silicone material being formed over
the passivation layer comprising polyimide; and the openings
through the silicone material to the bond pads also being formed
through the passivation layer comprising polyimide.
28. A method of fabricating integrated circuitry comprising:
providing a substrate comprising a plurality of integrated
circuitry die, individual of the die having bond pads; forming a
first blanket passivation layer over the substrate in contact with
the bond pads; forming a different second blanket passivation layer
comprising a silicone material over the first passivation layer;
forming openings through the first and second passivation layers to
the bond pads; and after forming the openings, singulating the die
from the substrate.
29. The method of claim 28 wherein the first passivation layer
consists essentially of silicon dioxide.
30. The method of claim 28 wherein the second passivation layer is
formed on the first passivation layer.
31. The method of claim 28 wherein at least one different
additional passivation layer is formed over the first passivation
layer prior to forming the different second passivation layer, and
such that the different second passivation layer is not formed on
the first passivation layer.
32. The method of claim 28 wherein at least two different
additional passivation layers are formed over the first passivation
layer prior to forming the different second passivation layer, and
such that the different second passivation layer is not formed on
the first passivation layer.
33. The method of claim 28 wherein the different second passivation
layer is of a photoimageable composition, and the openings are
formed by photolithography and etch which are void of any
photoresist layer received over the passivation layer comprising
photoimageable silicone material.
34. The method of claim 28 comprising forming the second
passivation layer comprising silicone material to have a Young's
modulus of no greater than 9.0 GPa.
35. The method of claim 28 comprising after the singulating,
contacting the second passivation layer comprising silicone
material with a solid particle containing resin.
36. The method of claim 28 wherein the die as singulated from the
substrate comprise an outermost layer predominately comprising the
second passivation layer comprising silicone material.
37. The method of claim 28 comprising forming the first passivation
layer over another passivation layer, and forming openings to the
bond pads through the another passivation layer prior to forming
the first passivation layer.
Description
TECHNICAL FIELD
[0001] This invention relates to methods of fabricating integrated
circuitry.
BACKGROUND OF THE INVENTION
[0002] Integrated circuitry fabrication typically fabricates
multiple discrete integrated circuits or chips over a single
substrate. A typical substrate utilized today is a monocrystalline
silicon wafer within and upon which integrated circuitry is
fabricated. Regardless, at the completion of fabrication, the
substrate is cut or otherwise processed to singulate the die into
individual integrated circuitry chips/die. Typically, the
individual chips/die are mounted and electrically connected with
larger circuit boards, lead frames or other substrates which
connect or otherwise become a part of some form of larger operable
hardware.
[0003] In many applications, the individual die as
connected/mounted to another substrate are encapsulated in epoxy
resin mold materials for fixating and protecting the mounted chip.
Typically, the epoxy mold compounds have a much higher thermal
coefficient of expansion than that of the typical silicon die and
even other substrate materials to which the die are mounted. These
differences in thermal coefficients of expansion can result in
considerable internal stresses in the ultimately encapsulated
device, in some cases leading to circuitry failure.
[0004] One manner of overcoming the stress caused by differences in
thermal coefficients of expansion includes silicon dioxide filler
materials within the mold compound. Typically, the intent and
effect is to modify the thermal coefficient of expansion of the
pure molding material to better approximate that of the die and
other substrate materials. Unfortunately, the hard silicon dioxide
particles can create their own problems. Specifically, upon
application and cure of the molding material, the silicon dioxide
particles can penetrate into the outer passivation layers
fabricated on the chip. This can result in the cracking of those
layers as well as the material of the integrated circuitry
underlying the passivation layers and lead to failure.
[0005] While the invention was motivated in addressing the above
issues and improving upon the above-described drawbacks, it is in
no way so limited. The invention is only limited by the
accompanying claims as literally worded (without interpretative or
other limiting reference to the above background art description,
remaining portions of the specification or the drawings) and in
accordance with the doctrine of equivalents.
SUMMARY
[0006] The invention includes methods of fabricating integrated
circuitry. In one implementation, a substrate comprising a
plurality of integrated circuitry die is provided. The individual
die have bond pads. A passivation layer comprising a silicone
material is formed over the bond pads. Openings are formed through
the silicone material to the bond pads. After the openings are
formed, the die are singulated from the substrate.
[0007] In one implementation, a method of fabricating integrated
circuitry includes providing a substrate comprising a plurality of
integrated circuitry die. Individual of the die have bond pads. A
first blanket passivation layer is formed over the substrate in
contact with the bond pads. A different second blanket passivation
layer comprising silicone material is formed over the first
passivation layer. Openings are formed through the first and second
passivation layers to the bond pads. After the openings are formed,
the die are singulated from the substrate.
[0008] Other aspects and implementations are contemplated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Preferred embodiments of the invention are described below
with reference to the following accompanying drawings.
[0010] FIG. 1 is a diagrammatic top view of an exemplary substrate
at a processing step in accordance with an aspect of the
invention.
[0011] FIG. 2 is a diagrammatic sectional view taken through line
2-2 in FIG. 1.
[0012] FIG. 3 is a view of the FIG. 2 substrate at a processing
step subsequent to that shown by FIG. 2.
[0013] FIG. 4 is a view of the FIG. 3 substrate at a processing
step subsequent to that shown by FIG. 3.
[0014] FIG. 5 is a view of the FIG. 4 substrate at a processing
step subsequent to that shown by FIG. 4.
[0015] FIG. 6 is a view of the FIG. 5 substrate at a processing
step subsequent to that shown by FIG. 5.
[0016] FIG. 7 is a view of the FIG. 6 substrate at a processing
step subsequent to that shown by FIG. 6.
[0017] FIG. 8 is a view of the FIG. 7 substrate at a processing
step subsequent to that shown by FIG. 7.
[0018] FIG. 9 is an alternate embodiment of the FIG. 5 substrate at
a processing stop subsequent to that depicted by FIG. 5.
[0019] FIG. 10 is a view of the FIG. 9 substrate at a processing
step subsequent to that shown by FIG. 9.
[0020] FIG. 11 is an alternate embodiment of the FIG. 4 substrate
at a processing stop subsequent to that depicted by FIG. 4.
[0021] FIG. 12 is a view of the FIG. 11 substrate at a processing
step subsequent to that shown by FIG. 11.
[0022] FIG. 13 is a view of the FIG. 12 substrate at a processing
step subsequent to that shown by FIG. 12.
[0023] FIG. 14 is a view of the FIG. 8 substrate at a processing
step subsequent to that shown by FIG. 8.
[0024] FIG. 15 is a view of the FIG. 14 substrate at a processing
step subsequent to that shown by FIG. 14.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] This disclosure of the invention is submitted in furtherance
of the constitutional purposes of the U.S. Patent Laws "to promote
the progress of science and useful arts" (Article 1, Section
8).
[0026] In accordance with aspects of the invention, and by way of
example only, preferred methodical embodiments are described with
reference to FIGS. 1-12. The illustrated relationships between the
various layers and die are exaggerated in the figures for clarity,
and are only diagrammatic depictions thereof. Referring initially
to FIGS. 1 and 2, a substrate in the form of a semiconductor wafer
is indicated generally with reference numeral 10. In the context of
this document, the term "semiconductor substrate" or
"semiconductive substrate" is defined to mean any construction
comprising semiconductive material, including, but not limited to,
bulk semiconductive materials such as a semiconductive wafer
(either alone or in assemblies comprising other materials thereon),
and semiconductive material layers (either alone or in assemblies
comprising other materials). The term "substrate" refers to any
supporting structure, including, but not limited to, the
semiconductive substrates described above. Substrate 10 has been
processed to include a plurality of integrated circuitry die 12.
Such have been fabricated to include a plurality of bond pads 14
which will be utilized ultimately in electrically connecting the
integrated circuitry of the die with external components.
[0027] Referring to FIG. 3, an exemplary first passivation layer 16
is formed over substrate 10 and in contact with bond pads 14. An
exemplary preferred material is undoped silicon dioxide, for
example deposited by decomposition of tetraethylorthosilicate
(TEOS). In one preferred embodiment, first passivation layer 16
consists essentially of silicon dioxide. By way of example only, a
thickness range for layer 16 is from 5,000 Angstroms to 10,000
Angstroms.
[0028] Referring to FIG. 4, another passivation layer 18 is formed
over and on (meaning in contact with) first passivation layer 16.
An exemplary material for layer 18 is silicon nitride, with layer
18 consisting essentially of silicon nitride in one preferred
embodiment. An exemplary preferred thickness range for layer 18 is
from 0.2 micron to 5 microns.
[0029] Referring to FIG. 5, another passivation layer 20 is formed
over and on passivation layer 18. A preferred material is
polyimide, with an exemplary preferred thickness range being from 1
micron to 10 microns.
[0030] Referring to FIG. 6, a passivation layer 22 comprising one
or more silicone materials is formed over and on passivation layer
20. Layer 22 is most preferably formed to have a Young's modulus of
no greater than 9.0 GPa. Exemplary preferred silicone materials
include those available from Dow Corning of Auburn, Mich. for
example the Dow Corning MXX-P family of silicones, with M300-P from
such family being one specific example. An exemplary such layer can
act as a stress buffer and preclude silica or other particles
within molding compounds or other materials from cracking layers
and other material therebeneath.
[0031] Referring to FIG. 7, a photoresist layer 24 has been formed
over passivation layer 22 comprising silicone material. A series of
openings 26 have been formed therein over bond pads 14. Referring
to FIG. 8, openings 26 have been extended through passivation
layers 22, 20, 18 and 16 to expose bond pads 14. Photoresist layer
24 would then be completely removed from the substrate. An
exemplary dry chemistry for etching through the silicone material
and polyimide material would be 02 plasma. Such would also
typically etch photoresist, which would warrant making the
photoresist layer sufficiently thick to complete etching through
the silicone material and the polyimide before the photoresist was
etched completely away. Silicon dioxide and silicon nitride can be
etched using CF.sub.4 and CHF.sub.3 chemistries.
[0032] Such provides but one example of forming openings through
the passivation layer 22 comprising silicone material to the bond
pads, with such method utilizing photolithography and etch
employing a photoresist that is completely removed from the
substrate prior to the singulating of the die from the substrate.
FIG. 9 illustrates an alternate embodiment processing with respect
to a substrate 10a. Like numerals from the first described
embodiment are utilized where appropriate, with differences being
indicated with the suffix "a" or with different numerals. In FIG.
9, a passivation layer 22a comprising a silicone material is formed
to be inherently photoimageable. An example preferred
photoimageable silicone material for passivation layer 22a is the
same M300-P material referred to above. Such can enable the
fabrication of the substrate using photolithography without using a
separate photoresist material which is ultimately removed from the
substrate. FIG. 9 depicts exemplary alternate processing to that
depicted by FIG. 8, whereby passivation layer 22a has been
photopatterned, for example utilizing a mask, with suitable actinic
energy effective to change the solubility in a solvent of selected
regions of the passivation layer which are received over bond pads
14. FIG. 9 depicts such substrate as having been exposed to a
suitable developing solvent effective to remove the selected
regions from over the bond pads, thereby forming exemplary openings
26 therein/in place thereof. Accordingly, if desired, such
processing can be essentially identical to that of FIG. 7, but void
of any photoresist layer over passivation layer 22a.
[0033] Referring to FIG. 10, the removed selected regions of
passivation layer 22a have been etched through, utilizing layer 22a
as a mask, layers 20, 18 and 16 to expose bond pads 14. Again and
preferably, such can be conducted without any use of photoresist
over layer 22a.
[0034] The above depicts but two example of forming openings
through silicone material containing passivation layer 22 to bond
pads 14, with each utilizing photolithography and etch. However,
other methods utilizing photolithography and etch, as well as
methods not utilizing photolithography and etch, are also
contemplated, and whether existing or yet-to-be developed. Further,
the above exemplary processing forms the passivation layer
comprising silicone material over one or more other passivation
layers, for example those comprising polyimide and silicon nitride.
One or both of the polyimide or silicon nitride layers might be
eliminated, or one or more other layers substituted therefor. The
same applies with respect to the preferred embodiment undoped
silicon dioxide passivation layer 16. Further, the orders of any of
the above layers could be switched or otherwise modified, with the
embodiment in the initially described order being but one preferred
example. Further but less preferred, the passivation layer
comprising the silicone material might be fabricated to be other
than the outermost layer. Also in the depicted and preferred
embodiments, the passivation layer comprising silicone material is
formed such that it is not in contact with bond pads 14, although
such could be fabricated to be in contact with bond pads 14.
[0035] FIG. 11 illustrates an alternate embodiment processing with
respect to a substrate 10b. Like numerals from the first described
embodiments are utilized where appropriate, with differences being
indicated with the suffix "b" or with different numerals. FIG. 11
illustrates processing subsequent to that of FIG. 4 whereby
openings 50 have been formed through layers 18 and 16 to bond pads
14. Such could be by photolithographic and etch manners, or by any
other means whether existing of yet-to-be-developed.
[0036] Referring to FIG. 12, a polyimide comprising passivation
layer 20b is formed over passivation layers 16 and 18 to within
openings 50. Silicone material comprising passivation layer 22 is
formed thereover.
[0037] Referring to FIG. 13, openings 26 are formed to bond pads
14. Again, such could be by photolithographic and etch manners, or
by any other means whether existing of yet-to-be-developed.
[0038] Referring to FIG. 14, die 12 have been singulated from
substrate 10/10a/10b. Such as singulated die comprise at least some
outermost layer, i.e., layer 22/22a, which predominately comprises
the passivation layer having the silicone material. Alternately,
the substrate might be fabricated such that the illustrated
uppermost/outermost layer does not predominately comprise the
passivation layer containing silicone material. Regardless if
desired, such can be mounted or otherwise provided with respect to
other substrates, and wire or other bond connections made through
the illustrated openings to the bond pads.
[0039] Referring to FIG. 15, an exemplary additional substrate 40
is shown bonded to die 12 using a resin 42 containing solid
particles 44. Such provides but one example of contacting the
passivation layer comprising silicone material with a silica
particle containing resin, in but one exemplary preferred
embodiment.
[0040] In compliance with the statute, the invention has been
described in language more or less specific as to structural and
methodical features. It is to be understood, however, that the
invention is not limited to the specific features shown and
described, since the means herein disclosed comprise preferred
forms of putting the invention into effect. The invention is,
therefore, claimed in any of its forms or modifications within the
proper scope of the appended claims appropriately interpreted in
accordance with the doctrine of equivalents.
* * * * *